s3sync comes with two utilities: s3sync.rb, which can backup a directory to S3 rsync-style, and s3cmd.rb, which gives you a command-line interface to S3. We’re actually not going to use s3sync.rb to backup our files (in the next blog post I’ll show you how to use astrails-safe instead). However, we will be using the s3cmd.rb utility now in order to interact with S3 from the command line.